Royal Dutch Shell said it will build the largest seagoing structure in the world, a floating liquefied natural gas vessel that will be parked over a massive gas field 125 miles off the coast of Australia.
The Prelude Floating LNG vessel will be 488 meters long – a few meters longer than the biggest oil tankers and longer than the Petronas Towers in Kuala-Lumpur are tall – and capable of producing the gas equivalent of 110,000 barrels per day of oil.
The $10 billion-plus facility will weigh around 600,000 metric tons fully loaded, or six times as much as the largest aircraft carrier. Some 260,000 tons of that weight will be just steel, which is about five times more than was used to build the Sydney Harbor Bridge, the company said.
The facility will let the company develop gas fields that normally wouldn’t be practical to develop because of their distance from shore.
First shipments could be made as early as 2016.
Shell has been working in the floating LNG arena for about 15 years, said Neil Gilmour, general manager for Shell Upstream’s Floating LNG business.
In the 1990s offshore Namibia and Nigeria were among the first areas considered for floating LNG, but the Namibian upstream reserves didn’t appear capable of supporting such a project while the technology didn’t seem advanced enough at the time to work in Nigeria.
A combination of factors led to the final decision for the Prelude FLNG project, Gilmour said.
First was the discovery of the large Prelude gas field in 2007, which is 100 percent Shell-owned, in a region where the company is planning as much as $30 billion in development in the next five years.
Next there was some 1.6 million man hours of working through the engineering challenges of fitting what is typically a land-based facility onto a floating space about one-fifth the size.
A key point was the early environmental and safety reviews from regulators, which came back with positive results.
There were nearly 3,000 engineering drawings done for the project, Gilmour said. “But the first time we saw a 3-D model of it was really a thing of beauty.”
The vessel is expected to stay moored in one place for about 25 years before being moved to other fields.
because of its size, the ship will be able to withstand a Category 5 cyclone, Shell said.
The vessel will be built in Dry Dock No. 3 at Samsung’s Geoje Shipyard in South Korea, one of the few places in the world capable of handling a ship of that size.
Shell isn’t specifying the price tag for the Prelude FLNG vessel, but its cost has previously been estimated to be between $10 billion and $12 billion.
Other similar vessels are being considered for offshore gas fields around the world, including the Greater Sunshine project in East Timor. Gilmour said Shell is also eying projects in Indonesia, the South China Sea, Cypress, East Africa and Latin America.
“Essentially we’re putting out a big ‘Open For Business’ sign with this project,” Gilmour said.
A few other numbers related to the project:
- Annual energy production: 3.6 million tons of LNG, 1.3 million tons of condensate and 400,000 tons of liquefied petroleum gas.
- No. of engineers on the project: 600
- 4 soccer fields, laid end to end, would be shorter than the facility’s deck
- 75 Olympic-sized swimming pools could hold the same amount of liquid as the facility’s storage tanks
- 6,700 horsepower will be the power of each of the three thrusters used to steer the facility
- 50 million liters of cold water will be drawn from the ocean every hour to help cool the natural gas
- 6 of the largest aircraft carriers would displace the same amount of water as the facility
- 105 meters is the height of the turret that runs through the facility, secured to the seabed by mooring lines
- -162° Celsius is the temperature at which natural gas turns into LNG
- 1/600 is the factor by which a volume of natural gas shrinks when it is turned into LNG
- 90 percent of Hong Kong’s annual energy demand could be met by the facility’s annual LNG production